Annexin A5 promotes invasion and chemoresistance to temozolomide in glioblastoma multiforme cells

Combined Effects of Annexin A5 Overexpression, 5-Fluorouracil Treatment, and Irradiation on Cell Viability of Caski Cervical Cancer Cell Line

Cervical cancer is the fourth leading cause of cancer deaths in women globally. Combining gene therapy with chemo- and radiotherapy may improve cervical cancer treatment outcomes. This study evaluated the effects of Annexin A5(ANXA5) overexpression alongside 5-fluorouracil (5-FU) and irradiation on the viability of CaSki cervical squamous cell carcinoma (SCC) cells. pAdenoVator-CMV-ANXA5-IRES-GFP-plasmid and mock plasmid were transfected into CaSki cells using calcium-phosphate. Seventy-two hours post-transfection, GFP expression was quantified by fluorescence microscopy and flow cytometry to evaluate transfection efficiency. ANXA5 overexpression was confirmed via qPCR. Twenty-four hours post-transfection, cells received a single dose of 8 Gy and were treated with 1 and 2 µg/ml of 5-FU (IC50 = 2.783 µg/ml). Cell viability, apoptosis, cell cycle stage, and Bcl-2 and Bax gene expression were assessed via MTT, annexin V/7-AAD, PI staining, and qPCR assays, respectively. ANXA5 was overexpressed 31.5-fold compared to control (p < 0.0001). MTT assays showed ANXA5 overexpression dose-dependently reduced CaSki cell viability (p < 0.001). IC50 of 5-FU was reduced from 2.783 μg/mL to 1.794 μg/mL when combined with ANXA5 overexpression. Additive effects on cell death were observed for ANXA5 plus 5-FU or irradiation versus ANXA5 alone. Apoptosis assays indicated combinatorial treatment increased CaSki cell apoptosis over ANXA5 alone. Cell cycle analysis revealed ANXA5 arrested cell cycle at G1/S phases; the percentage of cells in the S phase further rose with combination treatment. Finally, combination therapy significantly decreased Bcl-2 expression and increased Bax versus control (p < 0.001). Altogether, ANXA5 overexpression alongside 5-FU and irradiation may improve cervical squamous cell carcinoma (SCC) treatment efficacy. Further, in vivo investigations are warranted to confirm these in vitro results.

The Relevance, Predictability, and Utility of Annexin A5 for Human Physiopathology

As an important functional protein molecule in the human body, human annexin A5 (hAnxA5) is widely found in human cells and body fluids. hAnxA5, the smallest type of annexin, performs a variety of biological functions by reversibly and specifically binding phosphatidylserine (PS) in a calcium-dependent manner and plays an important role in many human physiological and pathological processes. The free state hAnxA5 exists in the form of monomers and usually forms a polymer in a specific self-assembly manner when exerting biological activity. This review systematically discusses the current knowledge and understanding of hAnxA5 from three perspectives: physiopathological relevance, diagnostic value, and therapeutic utility. hAnxA5 affects the occurrence and development of many physiopathological processes. Moreover, hAnxA5 can be used independently or in combination as a biomarker of physiopathological phenomena for the diagnosis of certain diseases. Importantly, based on the properties of hAnxA5, many novel drug candidates have been designed and prepared for application in actual medical practice. However, there are also some gaps and shortcomings in hAnxA5 research. This in-depth study will not only expand the understanding of structural and functional relationships but also promote the application of hAnxA5 in the field of biomedicine.

Annexin A5 suppression promotes the progression of cervical cancer

BACKGROUND

Cervical cancer is a common malignant gynecological disease that threatens the health of women all over the world. The abnormal expression of Annexin A5 (ANXA5) is closely related to the biological behavior of various malignant tumors, however, the relationship between ANXA5 and cervical cancer is still unclear. Therefore, the effects of low expression of ANXA5 on the proliferation, apoptosis, migration and invasion of cervical cancer cells (HeLa) and its related mechanism were explored.

METHODS

The cells were divided into three groups: ANXA5-si group, negative control group and blank group. RNA interference was used to suppress ANXA5 expression. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, colony formation assay, flow cytometry and propidium iodide (PI) staining, wound healing assay and transwell assay were employed to detect cell proliferation, apoptosis, migration and invasion respectively. Meanwhile, gene expression was detected by qPCR and Western blotting.

RESULTS

ANXA5 suppression lead to the increase of proliferation, migration, invasion and the decrease of apoptosis of cervical cancer HeLa cells. Furthermore, the expression of both pPI3K and pAkt increased.

CONCLUSION

ANXA5 might inhibit Hela cells proliferation and metastasis by regulating PI3K/Akt signal pathway.

Matrix Metalloproteinases in Chemoresistance: Regulatory Roles, Molecular Interactions, and Potential Inhibitors

Cancer is one of the major causes of death worldwide. Its treatments usually fail when the tumor has become malignant and metastasized. Metastasis is a key source of cancer recurrence, which often leads to resistance towards chemotherapeutic agents. Hence, most cancer-related deaths are linked to the occurrence of chemoresistance. Although chemoresistance can emerge through a multitude of mechanisms, chemoresistance and metastasis share a similar pathway, which is an epithelial-to-mesenchymal transition (EMT). Matrix metalloproteinases (MMPs), a class of zinc and calcium-chelated enzymes, are found to be key players in driving cancer migration and metastasis through EMT induction. The aim of this review is to discuss the regulatory roles and associated molecular mechanisms of specific MMPs in regulating chemoresistance, particularly EMT initiation and resistance to apoptosis. A brief presentation on their potential diagnostic and prognostic values was also deciphered. It also aimed to describe existing MMP inhibitors and the potential of utilizing other strategies to inhibit MMPs to reduce chemoresistance, such as upstream inhibition of MMP expressions and MMP-responsive nanomaterials to deliver drugs as well as epigenetic regulations. Hence, manipulation of MMP expression can be a powerful tool to aid in treating patients with chemo-resistant cancers. However, much still needs to be done to bring the solution from bench to bedside.

The prognostic significance of annexin A family in glioblastoma

BACKGROUND

Glioblastoma (GBM) is the most common histological type of glioma, which has the most aggressive biological characters and the worst outcome. The targeted therapy of GBM requires more progression, and new biomarkers should be identified.

MATERIALS AND METHODS

In our study, we firstly retrieved the data of TCGA and compared the TPMs of all ANXAs in TCGA database. By quantitative PCR (qPCR), we detected the mRNA levels of ANXAs in 8 pairs of GBM tissues and their corresponding normal brain tissues. Moreover, we detected the expression of ANXAs in 118 cases of GBMs, and further evaluated their clinical significance by analyzing the correlation with clinicopathological factors, and estimated their prognostic significance with univariate and multivariate analyses.

RESULTS

In the TCGA database, ANXA1, ANXA2, ANXA4, and ANXA5 had higher transcripts per million (TPMs) in GBM tissues compared with the normal brain tissues, while ANXA3 expression was downregulated in GBM tissues. With qPCR, ANXA1, ANXA2, and ANXA10 were verified to be the upregulated genes in GBM, but other ANXAs had no significant differences. ANXA2 and ANXA10, but not ANXA1, were correlated with poor prognosis of GBM and identified as independent prognostic biomarkers for poor outcome.

CONCLUSIONS

ANXA1, ANXA2, and ANXA10 are the upregulated genes in GBM. ANXA2 and ANXA10, but not ANXA1, are independent prognostic biomarkers indicating unfavorable outcome. Our results suggest that expression profiles based on ANXA10 expression may be a new classification system to predict prognosis of GBM patients.

AnnexinA5 Might Suppress the Phenotype of Human Gastric Cancer Cells via ERK Pathway

Gastric cancer is one of the most fatal diseases around the world. However, the mechanism of the development of gastric cancer is still not clarified. In addition, the anticancer drugs have cytotoxicity with different degrees. AnnexinA5, a member of the annexin family, has a great binding ability with the membrane phospholipid in a calcium dependent manner and is involved in the development of various cancers. This study aims to explore the influence of annexinA5 on human gastric cancer cells and whether it has the potential to be an auxiliary treatment to gastric cancer. In this study, the role of annexinA5 was detected from both the endogenous and the exogenous aspects on the gastric cancer cell lines MGC-803 and MKN-45. The cells were divided into a knockdown group in which RNA interference technique was used to suppress annexinA5 expression and a protein-supplementing group in which annexinA5 protein was added in the culture supernatant. After the suppression ratio of RNA interference was determined and the IC50 of annexinA5 protein was decided respectively, the cells' proliferation was detected by MTT assay, colony formation assay, and the expression of PCNA. FCM assay and PI staining methods were applied to test cell apoptosis and necrosis. To investigate whether ANXA5 influence cell metastasis, wound healing assay and transwell assay were employed. To further detect the mechanism of annexinA5 action, the signal pathway was examined with Western Blot method. When ANXA5 gene was knocked down, cell proliferation and metastasis were promoted, while cell apoptosis was suppressed. On the other hand, after the annexinA5 protein was applied to the gastric cancer cells, cell proliferation and metastasis were inhibited, while cell apoptosis and necrosis were promoted. AnnexinA5 played its role via ERK signal pathway. ANXA5 acted as tumor suppressor gene in the gastric cancer by suppressing ERK signal pathway and has the potentiality to be an auxiliary anticancer agent.

Secreted midbody remnants are a class of extracellular vesicles molecularly distinct from exosomes and microparticles

During the final stages of cell division, newly-formed daughter cells remain connected by a thin intercellular bridge containing the midbody (MB), a microtubule-rich organelle responsible for cytokinetic abscission. Following cell division the MB is asymmetrically inherited by one daughter cell where it persists as a midbody remnant (MB-R). Accumulating evidence shows MB-Rs are secreted (sMB-Rs) into the extracellular medium and engulfed by neighbouring non-sister cells. While much is known about intracellular MB-Rs, sMB-Rs are poorly understood. Here, we report the large-scale purification and biochemical characterisation of sMB-Rs released from colon cancer cells, including profiling of their proteome using mass spectrometry. We show sMB-Rs are an abundant class of membrane-encapsulated extracellular vesicle (200-600 nm) enriched in core cytokinetic proteins and molecularly distinct from exosomes and microparticles. Functional dissection of sMB-Rs demonstrated that they are engulfed by, and accumulate in, quiescent fibroblasts where they promote cellular transformation and an invasive phenotype.

Rai et al. characterise the properties of secreted midbody remnants, showing they are distinct from exosomes and microvesicles. The authors also find that these vesicles are engulfed by cells and promote anchorage independent growth and invasive phenotypes in NIH3T3 fibroblasts.

Loss of Annexin A5 expression attenuates the lipopolysaccharide-induced inflammatory response of rat alveolar macrophages

Acute lung injury (ALI) is a common respiratory syndrome accompanied with an inflammation response. Annexin A5 (AnxA5) has anti-thrombotic, anti-apoptotic, and anti-inflammatory properties. The current study aims to explore the potential effect of AnxA5 on lipopolysaccharide (LPS)-induced inflammatory response in alveolar macrophages (AMs). Rat AMs (NR8383) were used in this study, and the cell viabilities at 4, 8, and 16 h after LPS administration with gradient concentrations were determined using cell counting kit-8 assay. Cell apoptosis and expressions of messenger RNAs (mRNAs) and protein were determined by flow cytometry, quantitative real-time polymerase chain reaction (qRT-PCR), and western blot, respectively. We found that LPS suppressed the viability of AMs in a dose-dependent manner, and it elevated the expression of AnxA5 in AMs. Inhibition of AnxA5 improved the cell viability compared with the LPS group and could reduce the apoptosis rate in comparison with LPS treatment. The knockdown of AnxA5 suppressed the expressions of tumor necrosis factor-α (TNF-α), interleukin (IL-1β), and IL-6 at both protein and mRNA levels and regulated the expressions of apoptosis-related molecules (Bax, Bcl-2, and caspase-3). Moreover, the knockdown of AnxA5 improved the expression levels of inhibitory κB (IκB) and nuclear factor E2-related factor 2 (Nrf2) but inhibited the expression of nuclear transcription factor κB (NF-κB), compared with the LPS group. SN50 and ML385 were used to validate this signaling, and the inhibition of AnxA5 suppressed the LPS-induced inflammation, indicating that AnxA5 may be a potential anti-inflammatory target. In addition, NF-κB/Nrf2 signaling pathway may also be involved in the LPS-induced inflammatory response of rat alveolar macrophages.

Global extracellular vesicle proteomic signature defines U87-MG glioma cell hypoxic status with potential implications for non-invasive diagnostics

Purpose

Glioblastoma multiforme (GBM) is the most common and lethal of primary malignant brain tumors. Hypoxia constitutes a major determining factor for the poor prognosis of high-grade glioma patients, and is known to contribute to the development of treatment resistance. Therefore, new strategies to comprehensively profile and monitor the hypoxic status of gliomas are of high clinical relevance. Here, we have explored how the proteome of secreted extracellular vesicles (EVs) at the global level may reflect hypoxic glioma cells.

Methods

We have employed shotgun proteomics and label free quantification to profile EVs isolated from human high-grade glioma U87-MG cells cultured at normoxia or hypoxia. Parallel reaction monitoring was used to quantify the identified, hypoxia-associated EV proteins. To determine the potential biological significance of hypoxia-associated proteins, the cumulative Z score of identified EV proteins was compared with GBM subtypes from HGCC and TCGA databases.

Results

In total, 2928 proteins were identified in EVs, out of which 1654 proteins overlapped with the ExoCarta EV-specific database. We found 1034 proteins in EVs that were unique to the hypoxic status of U87-MG cells. We subsequently identified an EV protein signature, “HYP_SIGNATURE”, encompassing nine proteins that strongly represented the hypoxic situation and exhibited close proximity to the mesenchymal GBM subtype.

Conclusions

We propose, for the first time, an EV protein signature that could comprehensively reflect the hypoxic status of high-grade glioma cells. The presented data provide proof-of-concept for targeted proteomic profiling of glioma derived EVs, which should motivate future studies exploring its utility in non-invasive diagnosis and monitoring of brain tumor patients.

Electronic supplementary material

The online version of this article (10.1007/s11060-019-03262-4) contains supplementary material, which is available to authorized users.

Chemo-resistance of A172 glioblastoma cells is controlled by miR-1271-regulated Bcl-2

MicroRNAs (miRNAs) have been reported to exert important effects on the initiation, progression and metastasis of glioblastoma multiforme (GBM). In this study, we aimed to explore the regulation role of miR-1271 on the development of GBM. We found that miR-1271 was a Bcl-2-targeting miRNA, and the levels of miR-1271was decreased in samples from patients with GBM, compared with those from corresponding normal tissue samples. On the other hand, the levels of miR-1271 were inversely related to the levels of Bcl-2, which have been significantly increased in GBM samples. The overall survival was poorer in patients with low levels of miR-1271, compared to those with high levels of miR-1271. In vitro, the chemo-resistant cell survival mediated with Bcl-2 was inhibited by overexpression of miR-1271 and was enhanced by depletion of miR-1271. Thus, the chemo-resistance of GBM cells may be promoted after suppressing miR-1271 through cell survival mediated with Bcl-2. The prognosis of patients with GBM receiving chemotherapy may be improved by overexpressing miR-1271 in cancerous cells.

Molecular dissection of the valproic acid effects on glioma cells

Many glioblastoma patients suffer from seizures why they are treated with antiepileptic agents. Valproic acid (VPA) is a histone deacetylase inhibitor that apart from its anticonvulsive effects in some retrospective studies has been suggested to lead to a superior outcome of glioblastoma patients. However, the exact molecular effects of VPA treatment on glioblastoma cells have not yet been deciphered. We treated glioblastoma cells with VPA, recorded the functional effects of this treatment and performed a global and unbiased next generation sequencing study on the chromatin (ChIP) and RNA level. 1) VPA treatment clearly sensitized glioma cells to temozolomide: A protruding VPA-induced molecular feature in this context was the transcriptional upregulation/reexpression of numerous solute carrier (SLC) transporters that was also reflected by euchromatinization on the histone level and a reexpression of SLC transporters in human biopsy samples after VPA treatment. DNA repair genes were adversely reduced. 2) VPA treatment, however, also reduced cell proliferation in temozolomide-naive cells: On the molecular level in this context we observed a transcriptional upregulation/reexpression and euchromatinization of several glioblastoma relevant tumor suppressor genes and a reduction of stemness markers, while transcriptional subtype classification (mesenchymal/proneural) remained unaltered. Taken together, these findings argue for both temozolomide-dependent and -independent effects of VPA. VPA might increase the uptake of temozolomide and simultaneously lead to a less malignant glioblastoma phenotype. From a mere molecular perspective these findings might indicate a surplus value of VPA in glioblastoma therapy and could therefore contribute an additional ratio for clinical decision making.

AnnexinA5 promote glioma cell invasion and migration via the PI3K/Akt/NF-κB signaling pathway

As an important member of the Annexins, AnnexinA5 has been attributed important functions in trophoblast membrane repair, anticoagulation and cellular signal transduction. Accumulated studies show that AnnexinA5 is closely associated with various types of carcinomas. However, the potential contribution of AnnexinA5 to glioma cancer progression remains unclear. In this study, we report that AnnexinA5 is significantly upregulated in both high-grade glioma samples and glioma cell lines. Moreover, overexpression of AnnexinA5 promotes cell migration and invasion in vitro and tumorigenicity of glioma cells in nude mice, while knockdown of AnnexinA5 manifests a repressive function during these cellular processes. Importantly, mechanistic studies further reveal that AnnexinA5 is an essential transcriptional target of Snail via activating the PI3K/Akt/NF-κB signaling pathway. Taken together, these findings suggest that AnnexinA5 or the PI3K/Akt/NF-κB pathway may be promising therapeutic molecules to eradicate glioma metastases.

Tissue Proteome Analysis of Different Grades of Human Gliomas Provides Major Cues for Glioma Pathogenesis

Gliomas are heterogeneous and most commonly occurring brain tumors. Blood-brain barrier restricts the entry of brain tumor proteins into blood stream thus limiting the usage of serum or plasma for proteomic analysis. Our study aimed at understanding the molecular basis of aggressiveness of various grades of brain tumors using isobaric tagging for relative and absolute quantification (iTRAQ) based mass spectrometry. Tissue proteomic analysis of various grades of gliomas was performed using four-plex iTRAQ. We labeled five sets (each set consists of control, grade-II, III, and IV tumor samples) of individual glioma patients using iTRAQ reagents. Significantly altered proteins were subjected to bioinformatics analysis using Database for Annotation, Visualization and Integrated Discovery (DAVID). Various metabolic pathways like glycolysis, TCA-cycle, electron transport chain, lactate metabolism, and blood coagulation pathways were majorly observed to be perturbed in gliomas. Most of the identified proteins involved in redox reactions, protein folding, pre-messenger RNA (mRNA) processing, antiapoptosis, and blood coagulation were found to be upregulated in gliomas. Transcriptomics data of glioblastoma multiforme (GBM), low-grade gliomas (LGGs), and controls were downloaded from The Cancer Genome Atlas (TCGA) data portal and further analyzed using BRB-Array tools. Expression levels of a few significantly altered proteins like lactate dehydrogenase, alpha-1 antitrypsin, fibrinogen alpha chain, nucleophosmin, annexin A5, thioredoxin, ferritin light chain, thymosin beta-4-like protein 3, superoxide dismutase-2, and peroxiredoxin-1 and 6 showed a positive correlation with increasing grade of gliomas thereby offering an insight into molecular basis behind their aggressive nature. Several proteins identified in different grades of gliomas are potential grade-specific markers, and perturbed pathways provide comprehensive overview of molecular cues involved in glioma pathogenesis.

Proteomic Differences in Feline Fibrosarcomas Grown Using Doxorubicin-Sensitive and -Resistant Cell Lines in the Chick Embryo Model

Proteomic analyses are rapid and powerful tools that are used to increase the understanding of cancer pathogenesis, discover cancer biomarkers and predictive markers, and select and monitor novel targets for cancer therapy. Feline injection-site sarcomas (FISS) are aggressive skin tumours with high recurrence rates, despite treatment with surgery, radiotherapy, and chemotherapy. Doxorubicin is a drug of choice for soft tissue sarcomas, including FISS. However, multidrug resistance is one of the major causes of chemotherapy failure. The main aim of the present study was to identify proteins that differentiate doxorubicin-resistant from doxorubicin-sensitive FISS using two-dimensional gel electrophoresis (2DE), followed by matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) analysis. Using the three-dimensional (3D) preclinical in ovo model, which resembles features of spontaneous fibrosarcomas, three significantly (p ≤ 0.05) differentially expressed proteins were identified in tumours grown from doxorubicin-resistant fibrosarcoma cell lines (FFS1 and FFS3) in comparison to the doxorubicin-sensitive one (FFS5): Annexin A5 (ANXA5), Annexin A3 (ANXA3), and meiosis-specific nuclear structural protein 1 (MNS1). Moreover, nine other proteins were significantly differentially expressed in tumours grown from the high doxorubicin-resistant cell line (FFS1) in comparison to sensitive one (FFS5). This study may be the first proteomic fingerprinting of FISS reported, identifying potential candidates for specific predictive biomarkers and research targets for doxorubicin-resistant FISS.

Humanized chondroitinase ABC sensitizes glioblastoma cells to temozolomide

BACKGROUND

Malignant gliomas (glioblastomas; GBMs) are extremely aggressive and have a median survival of approximately 15 months. Current treatment modalities, which include surgical resection, radiation and chemotherapy, have done little to prolong the lives of GBM patients. Chondroitin sulfate proteoglycans (CSPG) are critical for cell-cell and cell-extracellular matrix (ECM) interactions and are implicated in glioma growth and invasion. Chondroitinase (Chase) ABC is a bacterial enzyme that cleaves chondroitin sulfate disaccharide chains from CSPGs in the tumor ECM. Wild-type Chase ABC has limited stability and/or activity in mammalian cells; therefore, we created a mutant humanized version (Chase M) with enhanced function in mammalian cells.

METHODS

We hypothesized that disruption of cell-cell and cell-ECM interactions by ChaseM and temozolomide (TMZ) will enhance the chemotherapeutic availability and sensitivity of glioma cells.

RESULTS

Utilizing primary patient-derived neurospheres, we found that ChaseM decreases glioma neurosphere aggregation in vitro. Furthermore, an oncolytic HSV-1 virus expressing secreted ChaseM (OV-ChaseM) enhanced viral spread and glioma cell killing compared to OV-Control, in vitro. OV-ChaseM plus TMZ combinatorial treatment resulted in a significant synergistic enhancement of glioma cell killing accompanied by an increase in apoptotic cell death. Intracellular flow cytometric analysis revealed a significant reduction in the phosphorylation of the pro-survival AKT protein following OV-ChaseM plus TMZ treatment. Lastly, in nude mice bearing intracranial GBM30 glioma xenografts, intratumoral OV-ChaseM plus TMZ (10 mg/kg by oral gavage) combination therapy resulted in a significant (p < 0.02) enhancement of survival compared to each individual treatment alone.

CONCLUSIONS

These data reveal that OV-ChaseM enhances glioma cell viral susceptibility and sensitivity to TMZ.

Lentivirus‑mediated knockdown of chondroitin polymerizing factor inhibits glioma cell growth in vitro

Glioma is the most common primary tumor in the central nervous system, characterized by rapid progression, aggressive behavior, frequent recurrence and poor prognosis. In the present study we demonstrated that chondroitin polymerizing factor (CHPF) is highly expressed in human glioma tissues and 4 glioma cell lines. To explore the role of CHPF in glioma, a lentiviral vector expressing CHPF shRNA was constructed and transfected into the glioma U251 cells, which stably downregulated the expression levels of the CHPF gene in U251 cells in vitro. U251 cell proliferation inhibition rates were determined by MTT assay. The effect of survivin shRNA on U251 cell cycle distribution and cell apoptosis was determined by flow cytometry. Compared to the shRNA‑Ctrl group of cells, the shRNA-CHPF group of cells exhibited decreased proliferation and a significant increase in the proportion of cells in the G0/G1 phase. In addition, we found that knockdown of the expression of CHPF increased apoptosis in glioma U251 cells. Therefore, our results confirmed that CHPF promotes growth and inhibits apoptosis in glioma U251 cells. Thus, by in vivo and in vitro data, the present study suggests that CHPF could be a new potential therapeutic target for glioma.

High Annexin A5 expression promotes tumor progression and poor prognosis in renal cell carcinoma

Annexin A5 has been found to act as an oncogenic protein in a variety of cancers. However, its specific biological role and mechanism in renal cell cancer (RCC) remains unknown. Quantitative Real-time PCR and western blotting were used to evaluate the mRNA and protein expression level of Annexin A5 in human RCC cell lines and tissues. Immunohistochemistry was adopted to measure the Annexin A5 expression in 123 cases of RCC tissues. Survival analysis was performed to explore the association between Annexin A5 expression and the prognosis of RCC. The effect of Annexin A5 on RCC growth and metastasis was studied in vitro and in vivo. Annexin A5 was frequently highly expressed in both human RCC cells and tissues. High Annexin A5 expression was associated with higher clinical stage and histological grade. In addition, Annexin A5 might be used as a predictive factor for the prognosis of RCC. Further research suggested that upregulated Annexin A5 in RCC cells could significantly promote tumor cell proliferation, migration and invasion in vitro. Subcutaneous xenograft tumor model displayed that knockdown of Annexin A5 could impede tumorigenesis in vivo. Moreover, mechanism study exhibited that Annexin A5 could activate PI3K/Akt/mTOR signaling pathway, promote epithelial-mesenchymal transition (EMT) and the expression of MMP2 and MMP9. Annexin A5 may be a potential prognostic biomarker in RCC and promotes proliferation, migration and invasion of RCC cells via activating PI3K/Akt/mTOR signaling pathway and regulating EMT process and MMP expression.

Secretagogin-dependent matrix metalloprotease-2 release from neurons regulates neuroblast migration

The rostral migratory stream (RMS) is viewed as a glia-enriched conduit of forward-migrating neuroblasts in which chemorepulsive signals control the pace of forward migration. Here we demonstrate the existence of a scaffold of neurons that receive synaptic inputs within the rat, mouse, and human fetal RMS equivalents. These neurons express secretagogin, a Ca²⁺-sensor protein, to execute an annexin V-dependent externalization of matrix metalloprotease-2 (MMP-2) for reconfiguring the extracellular matrix locally. Mouse genetics combined with pharmacological probing in vivo and in vitro demonstrate that MMP-2 externalization occurs on demand and that its loss slows neuroblast migration. Loss of function is particularly remarkable upon injury to the olfactory bulb. Cumulatively, we identify a signaling cascade that provokes structural remodeling of the RMS through recruitment of MMP-2 by a previously unrecognized neuronal constituent. Given the life-long presence of secretagogin-containing neurons in human, this mechanism might be exploited for therapeutic benefit in rescue strategies.

MiR-429 induces apoptosis of glioblastoma cell through Bcl-2

An essential role of microRNAs (miRNAs) has been acknowledged in the tumorigenesis of glioblastoma multiforme (GBM). Very recently, miR-429 was reported to have a potential of suppressing cancer growth. However, whether miR-429 may similarly regulate growth of GBM remains unknown. Here, we analyzed the levels of miR-429 and anti-apoptotic protein Bcl-2 in GBM specimens. We combined bioinformatics analyses and luciferase reporter assay to determine the relationship between miR-429 and Bcl-2 in GBM cells. Cell survival upon temozolomide treatment was analyzed in a CCK assay. Cell apoptosis was measured by fluorescein isothiocyanate (FITC) Annexin V apoptosis detection assay. We found that miR-429 levels were significantly decreased and Bcl-2 levels were significantly increased in GBM specimens, compared to the paired adjacent non-tumor brain tissue. Moreover, the levels of miR-429 and Bcl-2 inversely correlated. Low-miR-429 subjects had an overall inferior survival, compared to high-miR-429 subjects. MiR-429 targeted the 3'-UTR of Bcl-2 mRNA to inhibit its translation. Overexpression of miR-429 inhibited Bcl-2-mediated cell survival against temozolomide-induced apoptosis, while depletion of miR-429 augmented it. Together, our data suggest that miR-429 suppression in GBM promotes Bcl-2-mediated cancer cell survival against chemotherapy-induced cell death. Re-expression of miR-429 levels in GBM cells may improve the outcome of chemotherapy.

Quantitative Proteomic Profiling the Molecular Signatures of Annexin A5 in Lung Squamous Carcinoma Cells

Lung cancer remains the leading cancer killer around the world. It's crucial to identify newer mechanism-based targets to effectively manage lung cancer. Annexin A5 (ANXA5) is a protein kinase C inhibitory protein and calcium dependent phospholipid-binding protein, which may act as an endogenous regulator of various pathophysiological processes. However, its molecular mechanism in lung cancer remains poorly understood. This study was designed to determine the mechanism of ANXA5 in lung cancer with a hope to obtain useful information to provide a new therapeutic target. We used a stable isotope dimethyl labeling based quantitative proteomic method to identify differentially expressed proteins in NSCLC cell lines after ANXA5 transfection. Out of 314 proteins, we identified 26 and 44 proteins that were down- and up-regulated upon ANXA5 modulation, respectively. The IPA analysis revealed that glycolysis and gluconeogenesis were the predominant pathways modulated by ANXA5. Multiple central nodes, namely HSPA5, FN1, PDIA6, ENO1, ALDOA, JUP and KRT6A appeared to occupy regulatory nodes in the protein-protein networks upon ANXA5 modulation. Taken together, ANXA5 appears to have pleotropic effects, as it modulates multiple key signaling pathways, supporting the potential usefulness of ANXA5 as a potential target in lung cancer. This study might provide a new insight into the mechanism of ANXA5 in lung cancer.

Effect of temozolomide on the viability of musculoskeletal sarcoma cells

Musculoskeletal sarcomas (MSS) are a heterogeneous group of malignancies with relatively high mortality rates. The prognosis for patients with MSS is poor, with few drugs inducing measurable activity. Alkylating agents, namely ifosfamide and dacarbazine, which act nonspecifically on proliferating cells, are the typical therapy prescribed for advanced MSS. A novel alkylating agent, temozolomide (TMZ), has several advantages over existing alkylating agents. TMZ induces the formation of O⁶-methylguanine in DNA, thereby inducing mismatches during DNA replication and the subsequent activation of apoptotic pathways. However, due to conflicting data in the literature, the mechanism of TMZ action has remained elusive. Therefore, the present study aimed to evaluate apoptosis in MSS cells treated with TMZ, and to evaluate the correlation between TMZ action and survival pathways, including the phosphoinositide 3-kinase (PI3K)/Akt and extracellular signal-regulated kinase (ERK)1/2 mitogen activated protein kinase (MAPK) pathways. Cell proliferation was evaluated by performing an XTT (sodium 3'-[1-(phenylaminocarbonyl)-3,4-tetrazolium]-bis (4-methoxy-6-nitro) benzene sulfonic acid hydrate) assay. Apoptotic morphological changes, for example chromatin condensation, were evaluated by fluorescence confocal microscopy. The expression of the apoptosis-associated proteins caspase-3, poly adenosine diphosphate ribose polymerase (PARP), Akt and ERK1/2, was determined by western blotting. The results of the present study indicated that, in certain MSS cells, the IC₅₀ value was lower than that in TMZ-sensitive U-87 MG cells. Furthermore, TMZ treatment was associated with apoptotic morphological changes and the expression levels of pro-apoptotic cleaved caspase-3 and PARP were also increased in TMZ-treated MSS cells. In addition, the results indicated that PI3K/Akt and ERK1/2 MAPK were constitutively phosphorylated in MSS cells, and phosphorylation of PI3K/Akt was suppressed in certain cells, and maintained in other cells, by TMZ. These observations emphasized the plasticity of MSS cells, and suggested that this plasticity may contribute to the variance in cell sensitivity to TMZ and TMZ-resistance in MSS.

Biomarkers for glioma immunotherapy: the next generation

The term "biomarker" historically refers to a single parameter, such as the expression level of a gene or a radiographic pattern, used to indicate a broader biological state. Molecular indicators have been applied to several aspects of cancer therapy: to describe the genotypic and phenotypic state of neoplastic tissue for prognosis, to predict susceptibility to anti-proliferative agents, to validate the presence of specific drug targets, and to evaluate responsiveness to therapy. For glioblastoma (GBM), immunohistochemical and radiographic biomarkers accessible to the clinical lab have informed traditional regimens, but while immunotherapies have emerged as potentially disruptive weapons against this diffusely infiltrating, heterogeneous tumor, biomarkers with strong predictive power have not been fully established. The cancer immunotherapy field, through the recently accelerated expansion of trials, is currently leveraging this wealth of clinical and biological data to define and revise the use of biomarkers for improving prognostic accuracy, personalization of therapy, and evaluation of responses across the wide variety of tumors. Technological advancements in DNA sequencing, cytometry, and microscopy have facilitated the exploration of more integrated, high-dimensional profiling of the disease system-incorporating both immune and tumor parameters-rather than single metrics, as biomarkers for therapeutic sensitivity. Here we discuss the utility of traditional GBM biomarkers in immunotherapy and how the impending transformation of the biomarker paradigm-from single markers to integrated profiles-may offer the key to bringing predictive, personalized immunotherapy to GBM patients.